ISO/IEC INTERNATIONAL STANDARD 18477-9 First edition 2016-10-15 Information technology Scalable compression and coding of continuous-tone still images Part 9: Alpha channel coding Technologies de I'information-Compression échelonnable et codage d'imagesplatesentoncontinu Reference number ISO/IEC 18477-9:2016(E) TEC @IS0/IEC2016 IS0/IEC18477-9:2016(E) COPYRIGHTPROTECTEDDOCUMENT IS0/IEC 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISo at the address below or ISo's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org i ISO/IEC2016-Allrightsreserved IS0/IEC18477-9:2016(E) Contents Page Foreword ..iv Introduction. .. 1 Scope. ..1 2 Normative references 3 Terms,definitions, symbols and abbreviated terms. 3.1 Terms and definitions .1 3.2 Symbols.. 3.3 Abbreviatedterms .6 Conventions. 4 .6 4.1 Conformance language .6 4.2 Operators 6 .7 4.2.1 Arithmetic operators. 4.2.2 Logical operators.. 7 4.2.3 Relational operators .7 4.2.4 Precedenceorderofoperators 7 4.2.5 Mathematicalfunctions .8 5 General. .8 5.1 General definitions. .8 5.2 OverviewofIS0/IEC18477-9 .8 5.2.1 Encoder requirements .8 5.2.2 Decoderrequirements .8 Annex A (normative)Encoding and decodingprocess .10 AnnexB(normative)Boxes ..14 AnnexC (normative)Profiles .21 Bibliography .23 @IS0/IEC 2016 - All rights reserved ili